Dai Daoxin, Shi Yaocheng, He Sailing, Wosinski Lech, Thylen Lars
Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang Provincial Key Laboratory for Sensing Technologies, Zhejiang University, Hangzhou, China.
Opt Express. 2011 Jul 4;19(14):12925-36. doi: 10.1364/OE.19.012925.
A theoretical investigation of a nano-scale hybrid plasmonic waveguide with a low-index as well as high-index gain medium is presented. The present hybrid plasmonic waveguide structure consists of a Si substrate, a buffer layer, a high-index dielectric rib, a low-index cladding, a low-index nano-slot, and an inverted metal rib. Due to the field enhancement in the nano-slot region, a gain enhancement is observed, i.e., the ratio ∂G/∂g >1, where g and G are the gains of the gain medium and the TM fundamental mode of the hybrid plasmonic waveguide, respectively. For a hybrid plasmonic waveguide with a core width of w(co)=30nm and a slot height of h(slot)=50nm, the intrinsic loss could be compensated when using a low-index medium with a moderate gain of 176dB/cm. When introducing the high-index gain medium for the hybrid plasmonic waveguide, a higher gain is obtained by choosing a wider core width. For the high-index gain case with h(slot)=50nm and w(co)=500nm, a gain of about 200dB/cm also suffices for the compensation of the intrinsic loss.
本文对一种具有低折射率和高折射率增益介质的纳米级混合等离子体波导进行了理论研究。当前的混合等离子体波导结构由硅衬底、缓冲层、高折射率介质肋、低折射率包层、低折射率纳米槽和倒置金属肋组成。由于纳米槽区域的场增强，观察到增益增强，即∂G/∂g >1，其中g和G分别是增益介质的增益和混合等离子体波导的TM基模的增益。对于芯宽w(co)=30nm且槽高h(slot)=50nm的混合等离子体波导，当使用增益为176dB/cm的适度低折射率介质时，可以补偿固有损耗。当为混合等离子体波导引入高折射率增益介质时，通过选择更宽的芯宽可获得更高的增益。对于槽高h(slot)=50nm且芯宽w(co)=500nm的高折射率增益情况，约200dB/cm的增益也足以补偿固有损耗。
